How Effective Is a Low Carb Diet?

There is research to suggest following a low carb diet can lead to health benefits such as: weight loss, heart health and positive effects on blood glucose. Long term effects from following a low carb diet may need more research.

Following a low carb diet has become popular within recent years. Research has also supported some benefits with following a low carb diet associated with weight loss, heart health and blood glucose regulation.

A low carb diet is a shift from the popularity of a low fat diet trend. With the low fat diet, simple carbohydrate foods were exchanged for foods higher in fat.

For example, switching lower fat cookies in place of regular cookies may be seen as healthy even if the lower fat version is higher in sugar.

Swapping sugar or other simple carbohydrates in place of dietary fat is not recommended.

Lowering intake of sugar is recommended for all people, but following a low carb diet takes it a step further.

A low carb diet can mean different things, but generally speaking it reduces carbohydrate intake to about 80-240 calories per day.

In contrast, a typical American diet can provide around 800-1,000 calories per day from carbohydrates.

A low carb diet may be recommended for various medical conditions and for rapid weight loss.

However, keep in mind following a low carb diet doesn’t automatically mean it is healthy.

Incorporating a high amount of non-starchy vegetables, fruits (as allowed), nuts, seeds, heart healthy oils and lean proteins is an important foundation of a healthy low carb diet.

How to make a low carb diet healthy

A low carb diet may restrict carbohydrate intake to less than 250 calories per day (20-60 grams of carbohydrates). Some low carb diets may gradually increase carbohydrate amount over time.

This means the start of a low carb diet your intake of grains, legumes, fruits, dairy, starchy vegetables and sweets are cut out or severely restricted.

Over time, a certain amount of healthy carbohydrate sources like a variety of vegetables, fruits, legumes, whole grains and some dairy may be allowed back in.

Following a low carb diet should include a high amount of allowed vegetables, lean proteins, heart healthy fats.

As with any diet, it’s important to eat primarily nutrient dense foods while on a low carb diet. With the increase in popularity of low carb diets, beware there is an increase in processed foods that may fit into a low carb diet.

However, it’s important to know these foods are not necessary healthy.

Low carb diet and weight loss

According to Harvard School of Public Health (1), there is some evidence following a low carb diet may be beneficial for weight loss. The greatest benefit for low carb diet and weight loss is short term results.

Long term studies have some mixed results in concluding if a low carb has advantage over other diets for weight loss.

For example, a 2010 study (2) with a little over 300 subjects concluded after 2 years, successful weight loss can be achieved from a low carb or a low fat diet after 2 years.

Low carb diet and heart health

According to Harvard Health, research suggests a moderate low carb diet may be beneficial for heart health as long as foods provide healthy protein and fat qualities.

A 2015 critical review (5) on dietary carbohydrate restriction and diabetes management suggest there is strong evidence supporting the use of a low carb diet as the first approach for treating type 2 diabetes.

Is a low carb diet safe long term?

Safety of following a low carbohydrate diet long term is somewhat controversial. Some health professionals suggest there is no reason for harm for following a low carb diet long term, but some researchers suggest more studies looking at long term effects are needed.

Mayo Clinic (6) suggests severely restricting carbohydrate foods long term, like fruits and vegetables, may lead to increased risk for vitamin or mineral deficiency.

There may be side effects from starting a low carbohydrate diet such as: headache, muscle cramps, fatigue and digestive issues.

If you are wondering if you should start a low carb diet, you should consult your health care team.

Conclusion: Is a low carb diet healthy?

There is research to suggest following a low carb diet can lead to health benefits such as: weight loss, heart health and positive effects on blood glucose. Long term effects from following a low carb diet may need more research.

An important consideration for any diet pattern is to remember quality of food choices is just as important as quantity.

If you are following a low carb diet, it is important to make sure you are eating a variety of nutrient dense foods.

A 2018 report suggests the quality of ingested carbohydrates is more important than the quantity.

The consumption of carbohydrates that are high in fiber and slowly digested a moderate amount (40-50% of calories) may represent a scientifically based and palatable long term choice for people.

Following a strict low carb diet long term can be hard and may not be practical for some people.

Therefore, limiting carbohydrate intake to closer to 40-50% of calories may be more practical and still provide certain health benefits.

Whatever diet style you follow, sticking with consistent healthy, varied and nutrient dense foods is the most important component of any diet.

If you are considering a low carb diet, speak with your healthcare team first.

Author Info

Holly Klamer, RD Holly is a registered dietitian (RDN) with a MS degree in nutrition and exercise science. She teaches culinary nutrition classes at Kalamazoo Valley Community College. You can connect with Holly on LinkedIn.

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